Paper impervious to moisture, water, and grease



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v Ierent field of application than the paper from Patented Nov. 19,

UNITED STATES PATENT OFFlCE v PAPER INIPEBVIOUS TO MOISTURE, WATER, AND GREASE Edmond H. Buoy, Waukegan, 111., assignor to Atlas Powder Company, North Chicago, 111., a oorpo-, ration of Delaware 7 No Drawing. Application January 21, 1933, Serial N0. 652,938

14 Claims. (hi. 91-88) This invention relates to paper and it particuthat instance between coating. the stock and larly relates to such paper which is proof to wastacking or re-reeling it is too long and prohibiter in its liquid state as well as in vapor form and, tive. furthermore, is proof to grease, fats, paints and I have now found that I can produce a flexible similar substances, which when they incidentaland non-tacky paper rendered impervious to waly contact with and penetrate thepaperrender the same unsightly and unsuitable for the intended purposes.

There are papers on the market which'fill certain requirements exacted in this respect by the trade, but some of these papers are not physically resistant enough, or are not impervious enough, and are rendered unsightly, particularly when coming in contact with grease.

In the manufacture of impervious papers the cost of production is the point which invites careful attention, as such impervious papers, except in cases where transparency stands in the foreground, are mostly utilized for purposes where the expense must be lowered to a minimum.

For the manufacture of such impervious papers a great variety of substances have been applied, for instance, cellulose ester compounds, condensation products of formaldehyde and phenols, occasionally with admixtures of urea. Such papers are mostly suitable for special pur poses only; so the transparent papers made from cellulose derivatives are too costly except when they are to be used for wrapping papers lar to the latter by combining with the paper an 'oil soluble phenol condensation product with'a drying oil, casein, driers, plasticizers and dissolving these ingredients in various solvents.

As a phenol condensation product I may apply any member of the type i of the products obtained by condensing phenol with formaldehyde, including also the products obtained with other aldehydes, phenol-iuriural condensation products, cumarone-resln urea-formaldehyde condensation products, such as formaldehyde with a mixture of phenols and urea, the condensation products described by Buoy and Watkins in their application entitled Condensation products of phenol-phthaleinand filed in the United States Patent 0mce under Serial No. 629,878, and many other synthetic resins of similar character.

Another ingredient of the combination formcasein or such other adhesives, as glue, gelatine,

vegetable gums, such as dextrln, starch, gum

arable and the like. 1

These aforesaid materials are very suitable for where the contents are to be exposed to the in the Purposes of my invention, though I Prefer spection of the prospective customer. Other casein because of the dimculty 0f dissolving 111 n papers, comprising phenol cpndnsation prodwater. I dissolve the casein in ammonia water,

which I prefer to other alkaline dissolving agents because the ammonia readily escapes from the ucts, are not pliable enough tofind a utilization;

when paper is coated'with phenol condensation products it is usually turned into a still? board and I 1 t 't t a prgduct having quite g. revert to its insoluble condition. Casein is already widely used in the paper as a paper coating material, particularly in colored paper and it is also occasionally used as a binder.

In the present invention casein helps the phenol-formaldehyde, or other similar substance,

which it was made. By coating with phenol condensation products paper loses all elasticity and its original wide field of application is thereby reduced to one, relatively large, field, namely, that of serving as insulator in electrical devices. For other utilizations such paper is usually coated on its surfaces only with phenol-condensation products and is, moreover, toobrittle, so that 'it readily cracks as'to be unfit as a protection against water, or moisture, or grease and similar substances capable of permeating paper.

A drawback in the manufacture of paper coated with phenoliormaidehyde and similar condensation products is the rather long drying'period with the fibers or the same a kind oi felt, to render the paper grease-proof, and also aids in producing a flexible film, so that the final paper product can be bent without cracmng.

The drying oil which I prefer to apply is China wood oil, which may be replaced, though, in whole or in part by any other oils, such as linseed, castor, rape seed oil and like drying oils.

The application 0! driers depends on the final of such coatings. which almost make impossible requirements which the impervious paper is exthe application ,of such condensation products in pected to fulfill; thus iorinstance, the shade of a production where each step iollows the other in the desired product suggests occasionally a drier quick succession, the drying time required'in oflight color, or shows application oi a very film applied to the paper and allows the casein to ter, moisture, grease and other substances simiing the subject matter of this application 'is 95 to penetrate the body of the paper and to form of the applied oil calls occasionally for one drier in preference to another; however, cobalt lineolate and manganese rosinate have been found to give satisfactory results up to now, though any of the well known driers, as set forth in Martins Industrial Organic Chemistry, 1922, on

page 4'7, will do just as well.

I may also incorporate into the combination one or a plurality of stabilizers, or plasticizers, such .as triphenylphosphate, tricresylphosphate, triethanolamine and its soaps, borax, naphthenic acid, or any one of the number of other emulsion plasticizers.

In an example of one of the various ways of how Imay proceed in carrying my invention into effect I first cook the resin with oil to make up, preferably, a medium long oil varnish. The length in oil of the varnish is not critical of the final results and a considerable latitude in the quantity of oil is therefore allowed. For instance, I prepare in any of the well known ways a phenolformaldehyde resin of the type known to furnish a varnish when boiled with drying oils, such as linseed oil, China wood oil and other like drying oils, e. g. the types known in commerce by the trade names Bekalite", Paranol, Durite,

Bakelite.

After the first stage of reaction between the phenol and formaldehyde or formaldehyde developing substances has been reached, I separate the oily reaction products and heat the same in the way known to varnish makers at a temperature of from 200-500 C. with a drying oil, linseed oil, or China wood oil. I usually make a batch of twenty gallons of this varnish.

After the varnish has been cooked, it is adjusted with toluol, or a solvent known as V. M. 8: P. a trade term for paint makers naphtha, or a combination of the two, so that it contains 50% of solid and 50% of liquid ingredients. solvents of higher or lower boiling points may be applied for this purpose with the same result.

After the oil varnish has thus been made I introduce the casein solution. This casein solution is made by dissolving 1 lb. of casein for each gallon of water to which just enough ammonia water has been added to cause the casein to dissolve in the water when slightly warmed. Five gallons of such casein solution are added to five gallons of the oil varnish, which yields an emulsion of these substances. 1

Though the specific weight of the varnish, made as described above, varies of course within a rather wide. range according to the oils and solvents applied, it may be stated that five gallons of the varnish contain approximately 15-30 lbs. of solids; the proportion of casein to the of a natural resin solution, for instance, one

damar. At the same time also the small amount pint of damar solution, referably one in benzene, from which the wax has been removed and which contains 3 lbs. dewaxed damar resin per gallon. Other natural resins, similar in their properties to damar, may 'be added instead of of stabilizer, for instance, 60 gr. of triethanolamine, is introducedinto the mixture, which is then thinned with a varnish solvent, such as Other toluol, xylol, butyl-aicohol, turpentine, naphtha, benzene, etc., or with water. I

Finally I may add to-the emulsion a small amount of wax, for instance, 2 gr. of carnauba wax, or stearic acid, or paraflin, dissolved in a 5 volatile solvent, egg. toluene, per gallon of above mixture.

1 In order to introduce these waxes, or wax-like material, it may be necessary first to dissolve the solid wax-like material in appropriate solvent, preferably by the addition of a small amount. of heat. Thissolution maythen be' incorporated mechanically into the final emulsion.

The viscosity of the emulsion can be varied at will, as described further below; it may be applied by spraying, by a coating machine, swab or total immersion and this is thus obviously done in any of the well known ways.

The material, to which the emulsion is applied, may be paper of any commercial quality, in sheets, or long webs, or fabrics, or other stock of fibrous material.

This coating may also be used on fabrics, asbes- -tos sheeting or other material which may be coated in any of the well known manners as men- 25.

tioned above.

While I am aware that the emulsion may also be readily applied to transparent sheets, or webs,

1. A flexible sheet of paper coated with a composition comprising an oil soluble synthetic resin in solution in a drying oil, and an adhesive, said coat being proof to moisture, water and grease. 40

2. A flexible and non-tacky sheet of paper coated with a composition comprising an oil soluble condensation product of the phenol-formaldehyde type in solution in a drying oil, and an adhesive, said coat being proof to moisture, water and grease. a

3. A flexible sheet of paper coated with a composition comprising an oil soluble condensation product of the phenol-formaldehyde type in solution in a drying oil, and casein, said coat being proof. to moisture, water and grease. V

4. Aflexible sheet of paper coated with a composition comprising an oil soluble condensation product of the phenol-formaldehyde type in solution in a drying oil, an adhesive, driers, and a plasticizer, said coat'being proof to moisture, water and grease.

5. A flexible sheet of paper coated with a composition comprising an oil soluble condensation product of the phenol-formaldehyde type in solution in a drying oil, casein, driers, and a plasticizer, said coat being proof to moisture, water and rease.

6. A flexible sheet of paper coated with a composition comprising an oil soluble condensation product of the phenol-formaldehyde. type in solution in a drying oil, and an adhesive, said coat being proof to moisture, water and grease and, containing the adhesive and the phenol condensation product approximately within the limits between 1:2 and 1 :5 by weight, respectively.

7. A flexible sheet of paper coated with a composition. comprising an oil soluble condensation product of the phenol-formaldehyde type in solu- 1s tion ina drying oil, and an adhesive, said coat being proof to moisture, water and greaseand containing the adhesive and the phenol condensation product in the ratio 1:4, respectively.

8. A flexible sheet of. paper coated with a composition comprising an oil soluble condensation product of the phenol-formaldehyde type in solution in a drying oil, and casein, said coat being proof to moisture, water and grease and containing the-casein and the phenol condensation product approximately within the limits between 1:2 and 1:5 by weight, respectively.

9. A flexible sheet of paper coated with a composition comprising an oil soluble condensation product of the phenol-formaldehyde type in solution in a drying oil, and casein, said coat being proof to moisture, water and grease and containing the casein and the phenol condensation product in the ratio 1:4, respectively. 1

10.. A flexible sheet or paper coated with a composition comprising an oil soluble condensation .product of phenol and formaldehyde in solution in a drying oil, casein, and aplssticiur, said coat being proof to moisture, water and grease and.

containing the casein and the phenol-formaldehyde condensation product in the ratio 1:4, respectively. 10

12. A flexible sheet of paper coated with a composition comprising an oil soluble condensation product of the phenol-formaldehyde type in solution in linseed oil, casein, gum damar, triethanolamine; and carnauba wax, said coat being proof 15 to moisture, water and grease.

13. A flexible fibrous sheet material coated with an oil varnish in which are dissolved resins of the phenol-formaldehyde type, and an adhesive dispersed in said varnish.

14. A flexible ilbrous sheet material saturated with an oil varnish in which are dissolved resins of the phenol-formaldehyde type. and an adhesive dispersed in said varnish.

EDMOND H. BUC'Y. 25 

